GPT-6 Astra Explained: Price, Context Window and Specs
In short: GPT-6 Astra is an OpenAI model released on 3 September 2026, the first of OpenAI's sixth-generation GPT models. OpenAI describes it as its "most capable model for the most demanding work". It costs $10 per million input tokens and $50 per million output, has a 1,050,000-token context window and 128,000 tokens of output, reads text and images, and has a knowledge cutoff of 30 April 2026.
What is GPT-6 Astra?
GPT-6 Astra is a large language model from OpenAI, available in ChatGPT and through the OpenAI API. OpenAI's model page says to use it for complex reasoning, coding, computer use, research and document creation. The API model ID is gpt-6-astra.
The GPT-6 generation has more than one model. GPT-6 Sol, released later in September 2026, and its update GPT-6.1 Sol are lower-priced members of the family. For how GPT models work, see how LLMs work.
How much does GPT-6 Astra cost?
Input costs $10 per million tokens and output $50. From OpenAI's model page:
Three rules change the bill:
- Long prompts cost more. Prompts with more than 272K input tokens are priced at 2× the input and cache rates and 1.5× the output rate, for the whole request.
- Batch and Flex are half price. Both are priced at 50% of the standard rates.
- Fast mode costs double. It is priced at 2× the applicable rates.
For comparison, GPT-6.1 Sol costs $2 input and $10 output per million tokens.
What are GPT-6 Astra's specs?
| Spec | GPT-6 Astra |
|---|---|
| Developer | OpenAI |
| Released | September 3, 2026 |
| Model ID | gpt-6-astra |
| Context window | 1,050,000 tokens |
| Maximum input | 922,000 tokens |
| Maximum output | 128,000 tokens |
| Knowledge cutoff | 30 April 2026 |
| Input / output | Text and images in, text out |
| Reasoning effort | low, medium, high, xhigh, max |
| Features | Streaming, structured outputs, function calling, file search, web search, prompt caching |
| Not supported | Fine-tuning, audio, image generation |
The knowledge cutoff is the date the model's training data ends; without web search, it does not know about later events.
What are GPT-6 Astra's reasoning effort levels?
Effort controls how much the model reasons before answering - five settings for one model. OpenAI documents low, medium, high, xhigh and max. Higher settings spend more reasoning tokens, billed as output, before the reply. Leaderboards that test several settings list the same model once per setting.
What does OpenAI not publish about GPT-6 Astra?
OpenAI does not publish its parameter count, architecture details or training compute. Figures of that kind that circulate after launches are not from OpenAI's documentation.
How does GPT-6 Astra rank?
On LMArena's text leaderboard GPT-6 Astra has 1476 Elo (rank 37, max effort). GPT-6.1 Sol has 1481 Elo (rank 27, max effort). The full ranked table is on our benchmarks page.
Words to know
- Context window - the most tokens a model can handle in one request.
- Knowledge cutoff - the date the model's training data ends.
- Reasoning effort - how much the model thinks before answering.
- Cached input - repeated input billed at a lower rate.
- Batch / Flex - slower processing options billed at a discount.
- Fast mode - faster processing billed at a premium.
Related guides
Frequently asked questions
What is GPT-6 Astra?+
GPT-6 Astra is an OpenAI large language model released on 3 September 2026, the first of the GPT-6 generation. OpenAI describes it as its most capable model for the most demanding work, including complex reasoning, coding and research.
How much does GPT-6 Astra cost?+
It costs $10 per million input tokens and $50 per million output tokens, with cached input at $1. Prompts over 272K input tokens cost 2× for input and 1.5× for output, and Batch and Flex are half price.
What is GPT-6 Astra's context window?+
GPT-6 Astra has a 1,050,000-token context window, with up to 922,000 input tokens and 128,000 output tokens per request.
What is GPT-6 Astra's knowledge cutoff?+
OpenAI lists GPT-6 Astra's knowledge cutoff as 30 April 2026.
Can GPT-6 Astra read images?+
Yes. GPT-6 Astra accepts text and image input and returns text. It does not support audio input or image generation.
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